1. Field of Invention
This invention relates to a method for controlling and recovering hydrocarbon or certain low-polarity organic chemicals.
2. Brief Statement of the Prior Art
Hydrocarbon fuel, oil, and chemical spills occur frequently on a multitude of surfaces. On land, clay sorbents, cellulose or sphagnum products, surfactants, or other bioremedial methods to name a few are used in these situations with the intent of cleaning up the spill in a quick fashion or bioremediating a contaminated soil surface over time. On the water, spills tend to present unique problems and requires the responders to assess each spill quickly and choose among a variety of spill response products such as absorbents, adsorbents, gelling agents, sinking agents, surface washing agents, dispersants, biodegradation agents, biodegradation enhancers, de-mulsifiers, herding agents and approaches such as in situ burning. Factors such as cold water or broken ice conditions can change the physical state of crude oils making broad application of chemical dispersants more difficult and ineffective.
Various techniques and materials have been used as absorbents in helping to minimize contamination resulting from hydrocarbon fuel, oil, and chemical spills. Absorbents generally function by attracting materials to their pore spaces. Adsorbents such as polypropylene fibers function by hydrophobic nature in water and oleophilic attraction of the oil to wick into the surface area of the fiber.
Furthermore, various elastomeric materials of the prior art are disclosed regarding A-B-A triblock elastomers for hydrocarbon absorption during environmental cleanup on water. The A-B-A elastomers currently utilized include Styrene-Butadiene-Styrene, SBS or Styrene-Isoprene-Styrene, SIS (U.S. Pat. No. 3,518,183), Styrene-Butadiene-Styrene/Ethylene-Propylene Diene Monomer, SBS/EPDM (U.S. Pat. No. 6,344,519), Styrene-Ethylene-Butylene-Styrene, SEBS (U.S. Pat. No. 4,941,978 and U.S. Pat. No. 5,104,548), or Styrene-Ethylene-Propylene-Styrene, SEPS (U.S. Pat. No. 6,056,805).
Many of the prior art copolymers used in spill cleanup, due to their absorbent properties, are of the SEBS type copolymer. A SEBS type copolymer is a polystyrene-poly(ethylene/butylene)-polystyrene copolymer. Examples are KRATON G-1650 or KRATON G-1651 or KRATON G-1652 made by Shell Chemical Company. The KRATON G series, produced by anionic polymerization, are block polymers in which the elastomeric portion of the molecule is a saturated olefin polymer of the type ethylene/butylenes.
However, while the current triblock elastomers have been useful in containing spills, there remains a need for absorbents that have improved elasticity and tensile strength over the prior art with comparable softness. Moreover, there is a need for materials that reduce or eliminate oil bleed during spill absorption. Finally, there is a need for materials that can accomplish the aforementioned goals while remaining cost effective.